diff --git a/src/handlers.ts b/src/handlers.ts
index 344c7eaa..4abd2351 100644
--- a/src/handlers.ts
+++ b/src/handlers.ts
@@ -54,6 +54,7 @@ function defaultErrorHandler(err, req, res) {
         case 'ECONNRESET':
         case 'ENOTFOUND':
         case 'ECONNREFUSED':
+        case 'ETIMEDOUT':
           res.writeHead(504);
           break;
         default:
diff --git a/test/unit/handlers.spec.ts b/test/unit/handlers.spec.ts
index 385cc72c..b64a850a 100644
--- a/test/unit/handlers.spec.ts
+++ b/test/unit/handlers.spec.ts
@@ -104,6 +104,7 @@ describe('default proxy error handler', () => {
     ['ECONNREFUSED', 504],
     ['ENOTFOUND', 504],
     ['ECONNREFUSED', 504],
+    ['ETIMEDOUT', 504],
     ['any', 500],
   ];